- From: Amelia A Lewis <alewis@tibco.com>
- Date: Mon, 21 May 2007 14:37:48 -0400
- To: "Ramkumar Menon" <ramkumar.menon@gmail.com>
- Cc: "Jonathan Marsh" <jonathan@wso2.com>, www-ws-desc@w3.org
Heyo, On 2007-05-21 14:04:17 -0400 "Ramkumar Menon" <ramkumar.menon@gmail.com> wrote: > The specification of a uniqueness constraint is incompatible with the > optionality of the attribute. > > I am trying to understand the rationale of this explanation, but with > no > luck. :-( Maybe I am missing something here. > Would it be possible to elaborate more on this? It's possible that we missed something, in discussing this. We were under the impression that optional attributes could not be used in the selectors of unique constraints. Further, the validation that can be done using the unique constraint, when the target attribute is optional with defaulting rules that are also inexpressible in WXS, is less than ideal: <wsdl:operation> <!-- using default, so input-output --> <wsdl:output /> <wsdl:input /> <wsdl:output messageLabel="Out" /> <wsdl:input messageLabel="In" /> </wsdl:operation> This can't be caught with the uniqueness constraint (which is rather the purpose of the uniqueness constraint). If we can't catch such cases, then adding the unique constraint to the XSD is apt to suggest that all that needs to be checked is the result of that, when in fact it is entirely inadequate as a consequence of the optionality of the attribute and the rules for defaulting its value when it is missing. Note that the above fails for other reasons (not expressed in the schema, but expressible in the assertions of the component model). Amy! -- Amelia A. Lewis Senior Architect TIBCO/Extensibility, Inc. alewis@tibco.com
Received on Monday, 21 May 2007 18:38:00 UTC